Injection molding is commonly performed in the making of plastic parts. Such molding typically uses two or more mold components that are brought together (e.g., on platens) to form a mold cavity. When possible, such mold components are maintained at a generally static temperature that efficiently cools the molten resin injected into the cavity so that the resin solidifies quickly. The molding of a complicated part may require an elevated cavity surface temperature during the injection phase to ensure optimal feature replication. To meet this need, one or both mold components are sometimes heated prior to injecting the molten resin into the cavity, which may necessitate that one or both mold components be cooled after injecting the resin, in order to adequately solidify the resin. Such a variothermal injection molding process may often have a lengthened cycle time because of the need to remove the thermal energy stored in the (heated) mold components, above and beyond removing thermal energy from the molten resin itself